<div class="devui-scroll-container">
  <ul class="devui-scroll-content">
    <li class="item" *ngFor="let item of list; let index = index">
      {{ index + 1 + '. ' + item }}
    </li>
  </ul>
  <d-back-top
    [draggable]="true"
    [scrollTarget]="scrollElement"
    [right]="'60px'"
    [bottom]="'30px'"
    (backTopEvent)="backTop($event)"
  ></d-back-top>
</div>
